A known apparatus for anchoring a pulling member comprises an anchoring body formed as a molded piece with a transverse cross section small compared to its longitudinal cross section and an insertable guiding rod couplable detachably with it and alignable longitudinally with the anchoring body. The attaching piece for the pulling member is mounted laterally on the anchoring body with spacing from both ends of it (see U.S. Pat. No. 972,306 and German Pat. No. 27 11 979).
In one known ground or earth anchor an insertable anchoring body is used which has a rear end bent so that it is inclined with respect to the longitudinal axis of the anchoring body. On the side of the anchoring body opposite outwardly bent portion of its rear end between its center of gravity and that rear end, an attaching piece is provided for the pulling member.
According to U.S. Pat. No. 972,306 the anchoring body is a substantially flat steel plate with arrow shaped ends and a mounting shoe for the connecting or guiding rod is attached to one flat side of the steel plate by welding or riveting. Furthermore the mounting shoe has an eye for attachment of a pulling member. According to German Pat. No. 27 11 979 the anchoring body is made from a pipe section having a recess which is suitable for receiving the connecting or guiding rod and at its inside front end has a constricted section which is a bearing shoulder for the connecting or guiding rod.
The ground of German Pat. No. 27 11 979 has, in contrast to that of U.S. Pat. No. 972,306, an advantage, namely that it may be manufactured easily in one piece from a pipe section which need be provided with no additional elements of structures, since the attaching piece for the pulling member can be a handle or hook like piece of the pipe section cut out or pressed out of the pipe section.
Both above mentioned known ground or earth anchors have the disadvantage however that for automatic pivoting into their anchoring position with a force acting on the pulling member they must be cut not only at their rear end inclined to their longitudinal axes and must be provided with a lip shaped bent out section, but also simultaneously the attaching piece for the pulling member must be mounted so that it is found on the side opposing the bent out section of the rear end and between the center of gravity and the rear end.
Practical experience has shown that after erroneous insertion in unbroken ground or filled earth, these known earth or ground anchors cannot be removed but are lost unless dug out of the ground in a troublesome and time consuming way.
The desired withdrawal from the ground after erroneous insertion through the shaft in the earth formed by the anchor is prevented by the particular shape of its rear end cut inclined to its longitudinal axis and lip shaped bent outwards, a rearwardly directed force exerted by the pulling means invariably digs the anchor into the surrounding earth and as a consequence slants it in an undesirable way in the direction of its anchoring position even when it is still engaged with the connecting or guiding rod used to drive it into the ground.
These known earth or ground anchors can not be driven into stoney ground without problems. In case of the earth or ground anchor according to U.S. Pat. No. 972,306 the front point of the steel plate of the anchoring body is bent away laterally comparatively easily on encountering a flat thick stone and thus is prevented from further penetration to sufficient depth in the ground. Also the ground and/or earth anchor according to German Pat. No. 27 11 979 on account of its comparatively large circular front surface can not pass stones in its path and can be prevented from penetrating to a sufficient depth in the ground.